1. Field of Invention
The present invention relates to a pharmaceutical composition. More particularly, the present invention relates to a pharmaceutical acceptable composition containing a non-steroidal anti-inflammatory drug and a local anesthetic.
2. Description of Related Art
Among the herpes viruses, two commonly known viruses are herpes simplex virus types 1 and 2, referred to as HSV1 and HSV2 and varicella-zoster virus (VZV).
HSV1 causes orofacial lesions, commonly known as fever blisters or cold sores. These lesions most commonly appear on the lips, but may appear on the face, in the mucous membrane lining of the oral cavity, in the eye and nose, and occasionally on the trunk of hands. Infections of the mouth are designated with the term herpes labialis, also called cold sore (feverblister). Other parts of the face can also be affected and the infections thereof are referred to as facial herpes simplex. The infection can also manifest itself on other parts of the body. Approximately 30% of the United States population suffers from recurrent episodes of HSV1.
HSV2, which is less common than HSV1, causes genital lesions. Conversely, genital herpes is caused in about 30% of cases by HSV1.
Varicella-zoster virus (VZV) causes varicella, commonly known as chicken pox, and herpes zoster, commonly known as shingles. Shingles affects the skin and nerves and is characterized by groups of small blisters or lesions appearing along certain nerve segments. The lesions are most often seen on the back and may be preceded by a dull ache in the affected site.
Once an individual has been infected with the herpes virus, the virus will thereafter remain latently in the body. In latent state, the virus is situated in nerve cell bodies in the ganglia. Due to particular stimuli, such as influenza infection, other respiratory disorders, gastrointestinal infections, stress, fatigue, menstruation, pregnancy, allergy, sunlight, or fever, the latent virus can be activated and travel from the ganglia along the well-defined nerve paths to the skin surface and there multiply and cause the symptoms.
There is no treatment known to kill the herpes virus at this time. Most of the available treatments can only help to accelerate the healing of the lesions and the associated symptoms, but have not been shown to be efficacious in the treatment of herpes virus infections.
The best known treatment for herpes virus infections at this time is probably Zovirax® Ointment (Glaxo Wellcome), which contains the active ingredient acyclovir. Acyclovir, 9-(2-hydroxyethoxymethyl), is a purine nucleoside analogue targeting viral encoded DNA polymerase. Other purine nucleoside analogues which are commercially available for treating herpes virus infections include ganciclovir (Roche), penciclovir (Novartis) and foscarnet (Astra). Although effective, these purine nucleoside analogues are poorly soluble in water and demonstrate low bioavailability. These, accompanying the relative long recovery time required (i.e., generally takes longer than 2 weeks for patients to recover).
In the management of pain and discomfort, two kinds of drugs are widely used. The first kind is local anesthetics. Local anesthetics reversibly block the impulse conduction along nerves and other excitable membranes that primarily utilize sodium channels. Clinically, this action blocks the pain sensation from specific areas of the body.
Among the local anesthetics, lidocaine, 2-(diethylamino)-N-(2,6-dimethylphenyl)-acetamide, is particularly known for its treatment of ventricular tachycardia (an arrythmia of the heart) as an intravenous injection solution. (See e.g., U.S. Pat. No. 3,968,205). Lidocaine is also widely used as a vasoconstrictor to reduce regional blood flow in topical applications or aerosols (such as nasal aerosols to reduce nasal congestion). (See eg., U.S. Pat. No. 5,534,242). In addition, lidocaine is known for its therapeutic effects in reducing post-herpetic neuralgia (PHN) nerve injury pain from shingles (herpes zoster and post herpetic neuralgia) and analogous neuropathies. For example, U.S. Pat. No. RE37,727 discloses methods employing lidocaine intradermal administration by transport lidocaine from the skin surface, using patches and dressings, into the skin.
The second kind is non-steroidal anti-inflammatory drug (NSAID). NSAIDs are among the most widely used drugs, probably due to their therapeutic properties as anti-inflammatories, analgesics, anti-pyretics, and anti-thrombolics and are used to treat a variety of clinical conditions manifesting such symptoms as pain, inflammation, fever, and to treat and prevent atherosclerosis.
Among the NSAIDs, diclofenac, which is 2-(2,6-dichloro-anilino)-phenyl-acetic acid, is particularly known for its role as an anti-rheumatic agent for treatment of rheumatoid arthritis. Another NSAID similar to diclofenac and also belongs to the acetic acid class of NSAIDs is ketorolac. Ketorolac, which is 5-benzoyl-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid, is comparable to opioids in terms of providing pain relief. For example, the overall analgesic effect of 30 mg of ketorolac is equivalent to that of 6 to 12 mg of Morphine.